What is a data leak?

What are the differences between a data leak and a data breach?

A data leak is not the same as a data breach. Although the two terms are often confused, it's important to know how they differ.

Data leaks occur when companies expose data to external actors. For example, medical providers could leave computer displays in exposed positions. This potentially enables access to protected health information.

Data leaks often result from poor data privacy practices or weakly implemented security measures. Leaks are more likely to be unintentional than deliberate, and mitigation requires consistent auditing and staff training.

Data breaches happen when criminals exploit data leaks. Threat actors may deliberately breach network defenses to access, extract, and use information stored on private servers. Breaches can also involve physical theft or insiders passing information to criminals.

A data breach may also arise from flawed access controls or network security measures. Mitigation requires robust authentication and authorization policies and robust threat management tools.

Key takeaway: Companies can expose data without malicious outsiders taking action. Leaks can be intentional or accidental, but data breaches always involve intentional action to steal or exploit sensitive data.

How does a data leak happen?

Companies must understand how data leaks happen. Catastrophic data breaches affecting millions of customers often stem from a single data exposure.

Data leaks start with internal mistakes. They do not result from outsider surveillance and cyber-attacks. Leaks more commonly arise from insecure staff actions or security decisions. This happens for a variety of reasons, including:

• Human error: Human error is the most common cause of data leaks. Staff may accidentally email confidential information to many recipients or leave documents unattended. Policies to enforce safe data handling are essential.
• Infrastructure issues: Network configuration problems can put sensitive data at risk. For example, companies may fail to encrypt cloud data containers or enforce rigorous access controls.
• System failure: Network outages can compromise security measures and lead to data exposure. Software flaws can also expose personal information to threat actors. For example, faulty code in Facebook's phone-to-phone messaging feature exposed data from 530 million users.
• Insider threats: Malicious insiders can download or transfer sensitive data for sale or misuse. This is a particular issue for sales organizations where employees may steal client data for commercial gain.
• Third-party risk factors: Data leaks can arise from supply chain attacks or malicious third-party access. Companies must assess third-party risk as seriously as internal factors when protecting against leaks and breaches.
• Outdated systems: Finally, data leaks happen when companies lose track of their data assets. Systems age and security teams forget about data containers. Security controls no longer apply, and forgotten data becomes a data leak risk.

Types of data leaks

Data leaks come in many forms, which makes prevention challenging. Common types of data leaks include:

Email leaks

Email is a critical weak point when it comes to data leaks. Staff constantly send emails to clients, customers, and colleagues. They may need to transfer sensitive data in everyday duties. However, staff do not always do so safely.

Employees could accidentally send a confidential message to thousands of contacts. They might send confidential information without seeking authorization. This often occurs when staff don't understand the definition of "confidential" and managers do not routinely enforce authorization processes.

Shadow IT

Employees should follow secure practices when updating IT resources and handling data. However, time and cost pressures often lead to workarounds. IT teams also struggle to implement consistent security measures across large organizations.

Shadow IT emerges from this chaotic situation. It also creates significant data breach risks, for example, when users resort to unapproved third-party apps and cloud services to record their work or collaborate.

IT teams can't tell whether employees apply security settings on cloud drives. Sensitive data circulating on unapproved apps is potentially exposed to malicious outsiders.

Privilege escalations

Data exposure often happens when network users have too many privileges. Over-privileged users can access more data than is required for critical work tasks. Attackers gaining the login credentials of over-privileged users can roam the network and extract data. Conversely, companies can cut data breach risks by enforcing the principle of least privilege and restricting user permissions.

Third-party vulnerabilities

Companies rely on third parties to supply storage solutions, cloud platforms, and network apps. However, third-party products can lead to data leaks. In this type of data leak, third parties could fail to secure their products, putting client data at risk.

Clients can also give third parties too much access to network resources. Excessive access makes supply chain attacks against vendors far more damaging, highlighting the need for thorough access control policies.

Physical data leaks

Some data breach incidents start with a casually discarded document. Employees may throw away print documents containing personal health information or financial details. Without proper disposal or shredding, malicious actors can obtain valuable information.

The same applies to lost laptops, external drives, and work smartphones. Without encryption or device-disabling tools, criminals can easily access the data on lost or stolen devices.

Common causes of data leaks

We know the most common types of data leak, but what factors make data leaks more likely? The following list details the most significant causes of leaks to inform your data security strategy.

Falling for phishing scams

Data leaks could happen due to staff falling for phishing scams—a classic example of human error putting data at risk.

In phishing scams, criminals pose as legitimate contacts, usually via email. Employees believe criminals are legitimate and take recommended actions, such as downloading attachments or visiting fake websites. When they do so, criminals deliver malware, which leads to data breaches.

Action by malicious insiders

A data security incident often starts from the inside. Disgruntled employees and contractors may expose data for personal reasons, while insiders may leak data for financial or political gain.

In other cases, insiders have both political and personal motives. For instance, in 2023, Tesla admitted that two former employees had leaked data about Tesla employees and customer complaints to a German newspaper.

Poor physical security

Poor physical security measures can also lead to data leaks. For instance, staff could expose data by losing their work laptop and failing to encrypt confidential information. Failing to secure data storage servers raises the likelihood of data leaks. Writing passwords in physical notebooks and failing to dispose of devices securely are also common physical causes of data leaks.

Failing to manage software vulnerabilities

Data leaks happen when companies let their patch management systems slide. Unpatched or outdated software is vulnerable to exploit attacks. Slow updates can also leave users with the wrong permissions, enabling unauthorized access to confidential resources.

In other cases, companies fail to configure assets securely. For example, organizations may expose cloud databases to public internet users or improperly configure web APIs.

Inadequate password practices

Weak passwords expose data to credential-stuffing attacks. Employees may reuse passwords across multiple services. If they use the same login credentials to access sensitive data, password re-use significantly raises data leak risks.

Lack of knowledge and poor training

Data leaks often occur because companies fail to train staff and enforce data security policies. This is not the same as pure human error. Not training employees is an intentional mistake and something that responsible organizations take seriously.

For instance, companies may lack clear and accessible data-handling policies. Staff may not understand their compliance responsibilities or how to determine whether data is confidential.

How to prevent a data leak

Data leaks leading to breaches result in fines, identity theft attacks, and reputational damage. Companies need a robust strategy to prevent data leaks and minimize breach risks. Ingredients of an effective data protection plan include:

Use controls to prevent unauthorized access

Establishing access controls is the starting point for managing data breach risks. The core principle is that only users with a legitimate business justification should have access to sensitive data.

Multi-factor authentication requests more than one unique credential when users try to access confidential data. This blocks malicious actors with stolen credentials. Authorization systems should also assign appropriate privileges based on company roles. That way, attackers who successfully breach the network have limited access to network resources.

Create a data inventory and classify critical data

Companies must know the data they collect and store and where the data resides. An accurate and regularly updated data inventory allows security teams to classify data and implement targeted security measures.

Security teams should combine the data inventory with Data Loss Prevention (DLP) tools. DLP tools track data status, recording user requests to access, amend, move, or delete information. They generate alerts about suspicious activity while allowing employees freedom to work efficiently.

Write and implement robust data security policies

Data security policies document how an organization protects data against leaks and breaches.

Policies should explain what confidentiality and privacy mean in the business context. Employees must know when they are handling confidential information, and when looser data security rules apply. The policy must also include penalties for data misuse, including dismissal if necessary.

Security policies explain the measures to protect data, such as encryption, firewalls, DLP, and access controls. Automation tools help you implement these policies across all devices. Device posture security solutions also scan devices to ensure compliance and block insecure devices from connecting to the network.

Use patch management to update software

Outdated software can expose data to exploit attacks. Companies must adopt robust patch management to deliver vendor updates when available. Combine software updates with threat detection tools that scan for exploits and malware infections.

Enforce strict policies regarding shadow IT as well. Require the use of approved products when handling sensitive information. Do not allow user-supplied workarounds.

Adopt secure data storage and sanitization measures

Encryption is essential when guarding against data breach risks. Use robust encryption to protect all confidential data, whether stored on-premises or on cloud platforms. Require employees to use encrypted connections when sending sensitive data, including remote access tools like Virtual Private Networks (VPNs).

Organizations must also delete data they do not need (unless retention is essential for compliance purposes). Dispose of data and devices securely. Schedule regular audits to detect and delete obsolete data.

Train staff to understand data leak risks

Training is essential to prevent data leaks. Ensure staff understand data handling policies and can define confidential data. Staff should understand the causes of data breaches, such as allowing unauthorized access or failing to fix software vulnerabilities.

Remember: human error is often the starting point for company-wide data security incidents. Try to create a culture of data security, including regular workshops, training events, and communications from the security team.

Update your data protection systems to prevent data leaks

Data leaks unintentionally expose information that should remain private. Leaks occur for many reasons. Staff may accidentally email data or leave workstations unattended in public. Security controls may allow unauthorized access to network assets, while threat actors can exploit flaws in outdated software.

Whatever the root cause, data leaks can easily become severe data breaches, with damaging consequences for affected organizations. Adopt security best practices and train staff to guard against leaks and minimize data breach risks.